The recent development of large-area, flat-screen display panels opens a new dimension in the dissemination of alpha numeric and TV video information. Conventional cathode ray tube (CRT) displays utilize a scanning electron beam to address individual picture "points" on the screen. In the solid-state flat-panel display, addressing of individual points is accomplished by electronically selecting appropriate conducting bus bars which carry the required electrical signals to a matrix of "picture" elements located on the display surface.
A typical flat-panel display consists of a rectangular matrix of light-emitting or light-controlling elements, each element having associated with it a controlling circuit, located on a one-for-one basis next to the element. A cross grid of conducting bus bars is used to connect the individual picture elements to the "outside world" addressing system. Rather than having a single bus bar for each element, a coincidence addressing scheme is used whereby all elements in a given row are connected to one bus bar while all elements in a given column are connected to a bus bar running at right angles to the row bus bars. With this technique a panel containing a matrix of m by n elements would require m+n interconnections instead of m.times.n. Signals applied simultaneously to one row and to one column addresses the element located at the intersection of the two bus bars. In this manner the entire display panel is addressed by scanning all the row and column bus bars.
While the X-Y addressing scheme described above greatly reduces the number of panel interconnections, a cable containing in excess of 1,000 wires would be required to interconnect a panel having full TV resolution of say 500.times.500 lines. The need arises, therefore, to have a peripheral interface circuit which can be conveniently fashioned on, or connected to, the outer edges of the display panel which will address each of the X and Y bus bars and have a minimum number of external connecting leads. This invention discloses such a circuit.